Look for former first daughter Chelsea Clinton to step up her schedule on behalf of her mother's presidential campaign. "She's our not-so-secret weapon," says an aide. Chelsea's already visited about two dozen states, hitting lots of college campuses and generally campaigning on her own. Here's why we expect to see more of her: Associates say Chelsea's visits boost Sen. Hillary Clinton's election night numbers. One insider says there's "a direct correlation between Chelsea's visits and Hillary Clinton's performance."